VSS troubleshooting

VSS (Volume Shadow Copy Service, or Volume Snapshot Service), is a technology included in Microsoft Windows that allows taking manual or automatic backup copies or snapshots of computer files or volumes. The VSS captures and copies stable images for backup on running systems, particularly servers, without unduly degrading the performance and stability of the services they provide.

Important Note:
As part of the Microsoft Windows server operating system, VSS is not a product provided by Cloud Direct. This article is intended as a first step to help resolve VSS related issues affecting Cloud Direct's backup service. However, should VSS-related problems persist then please contact your local IT Support.


Checking VSS settings and logs

If LiveVault backups are failing intermittently due to VSS errors, then check the VSS settings and logs as follows.

Check VSS settings

  1. Refer to knowledge article, KB0011296, Checking and adjusting VSS thresholds to review your VSS/shadow copy set-up. Ensure that each Volume being backed up is set to Use Limit, with a maximum size VSS threshold set at 15% to 20% of total capacity for that drive.
  2. Disable the Windows snapshot utility in the Shadow Copies set-up window.
  3. Ensure each Volume on the server has a minimum of 20% free disk space (at the very least 320MB), available for VSS use.

Check VSS writers

Check the VSS writers log files (VSSadmin list writers, and VSSadmin list providers), for any problem indication.
  1. Refer to knowledge artilce, KB0011259, Collecting LiveVault log files in a Windows environment, for details of how to collect VSS writers logs.

Check logs

  1. Check your two Windows Event logs; System and Application, for VSS or Volsnap errors. These may lead you to a more exact fix. Refer to knowledge article, KB0011259, Collecting LiveVault log files in a Windows environment, for details of how to collect Windows System and Windows Application logs, and forward them to Cloud Direct.

If you are using a Linux environment, then refer instead to, KB0011291, Collecting LiveVault logs in a Linux environment.

Additional information

In addition to the information provided in this article, please refer to the following for more help with VSS troubleshooting:

  • LiveVault Help. Check LiveVault's product Help files.
  • Vssadmin utility. Look for errors or non-responses from the list writers and list providers. If the Vssadmin utility shows errors, then consider looking at re-registering VSS and rebuilding the COM+ layer, as detailed in the LiveVault Help section on Troubleshooting VSS.

Further help

If your LiveVault backups continue to fail, please contact Cloud Direct Technical Services for further assistance. Include a copy of the following logs with your request:

  • Windows Event logs (both System, and Application, Event logs), in .evtx format.
  • Windows System Information log, as a .nfo file.

(See Check logs, above for details of how to collect and send these logs).